Fiber arrays are used for various types of applications, such as silicon photonic (SiPh) systems, including optical switching for communications as well as sensing applications where spatial optical data is employed, such as DNA sequencing, astronomy and nuclear research. The ends of optical fibers of the fiber array are maintained in fixed positions using a fiber array block with grooves or channels. The optical fibers are aligned in relations to other components of the optical system, such as other optical fibers, a planar waveguide or an opto-electronic device.
Conventional fiber array blocks employ v-grooves to fix the positions of the optical fibers. The v-grooves are formed by wet chemical etching technology which requires the usage of alkaline solutions containing KOH. However, such KOH solutions often cause contamination issues. In particular, K+ ion is an extremely fast-diffusion alkali metal ion which is detrimental to metal oxide semiconductor (MOS) devices. Furthermore, handling fiber arrays contaminated with K+ ions can cause health issues, making them a safety hazard.
U-groove fiber array blocks have been investigated. U-grooves are formed by an excimer laser ablation technology. However, laser ablation is not capable of precisely controlling small core pitches due to large laser beam size, which typically is about a few square centimeters. This may result in optical fibers being loosely fitted into the u-grooves, adversely affecting coupling efficiency. In addition, laser ablation is not feasible for manufacturing commercial fiber arrays because of long processing time due to small beam size.
The present disclosure is directed to fiber array blocks and fiber arrays.